Electrically operated safety interlock for broaching machines



. C. F'. TRITELINE ETAL ELECTRICALLY OPERATED SAFETY INTERLOCK Jan. 27, 1953 FOR BROACHING MACHINES 2 SHEETS-SHEET l Filed May 19 1950 gig Jan. 27, 1953 c. F. TRITELINE ETAL ELECTRICALLY OPERATED SAFETY INTERLOCK FOR BROACHING MACHINES 2 SHEETS-SHEET 2 Filed May 19, 1950' @.LAWW

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Y /M/Wra/Ps c. E MHH/Ms' 5. l.. WIP/6197' Patented Jan. 27, 1953 ELECTRICALLY OPERATED SAFETY INTER.- LGCK FOR BROACHHNG MACHINES Charles F. Triteline, Downers Grove, and Benl L. Wright, Chicago, Ill., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application May 19, 1950, Serial No. 152,946

Claims. (Cl. 90-33) Y This invention relates to a safety interlock for i the control lever of a material working machine and more particularly to an electrically operated safety interlock for the control lever of a broaching machine for preventing the actuation of the breaching machine before the work holder of the machine is in its operative position.

It is an lobject of the present invention to provide aneicient and positive safety interlock for preventing improper operation of the control lever of a material working machine.

In accordance with one embodiment of the invention as applied to a hydraulically operated broaching machine having a lever for controlling the forward and return strokes of the breach, a movable control plate isprovided having an irregularly shaped aperturetherein through which extends an arm connected to and movable with the lever. The control plate is yieldably maintained in one position Where the aperture therein limits the movement of the operating lever to and from reverse and neutral positions, and the control plate is movable to a second position by a solenoid when energized in response to the movement of a work holding fixture of the broaching machine to its closed position. The control plate in its second position serves to limit the movement of the lever to and from forward and neutral positions so that only when the work holding fiX- ture is in its closed position may the lever be movedwto its forward position to effect the for- Ward stroke ofthe broach and then only after the work holding fixture has been moved to itsopen position may the operating lever be moved to its reverse position toeffect the return of the broach. Other objects and advantages of the invention will be apparent by reference to the following detailed description thereof and the accompanying drawings illustrating an embodiment of the invention in which f l l Fig. lis a side elevation view of a portion of a hydraulically actuated breaching machine with the invention applied thereto;

Fig. 2 is a vertical sectional view taken on the line of Fig. 1;

v3 is an enlarged fragmentary elevational viewy of the safety interlocking mechanismshown in Fig. 1 with the vcontrol plate in its normal position; v n

Fig. 4 is a. view similar to Fig. 3 showing the controlplate in a changed position; n Fig 5 is a horizontal sectional view taken on the line 2-2 of Fig. 3; y l l Fig. Gis a. lvertical sectional view'taken on the line 6-6 of Fig. 3,; and

Fig. '7 is a perspective view of the locking plate.

Referring to the drawings, the invention is shown applied to abroaching machine l0 having a vertically movable ram vI2 actuated by a hydraulic actuator (not shown) in response to the movements of a rod I4 which actuates the hydraulic control valves and is spring stressed downwardly to a normal or reverse position to cause the ram to return to its upper or starting position. The ram I2 is adapted to advance or move downwardly in response to an upward movement of the rodV I4 and is adapted to return or move upwardly in response to a downward movement of the rod I4. Control means are provided to reciprocate the rod I4 to effect the actuation of the ram' I 2. The end I6 of a lever I'I pivotally mounted at I8 on the broaching machine I0 is engageable with a collar 20 on the rod I4 for moving the rod upwardly in response to actuation of the lever I'I in one direction. At its other end the lever Il is connected to one end of a link 24, the other end of which is connected to a control lever 26 pivotally mounted on thev broaching machine at 2l and having a handle 28 by means of which the lever 26 may be moved downwardly to impart upward movement to the rod I4 to eiect the forward movement of the ram I2. When the operator removes his hand from the control handle in its lower position, the spring stressed rod I4 is returned to its reverse position and causes the upward movement of handle 28 as well as the ram I2.

Attached to the lower end of the ram I2 is a broach holding xture 3D the lower end of which engages in a guideway `in a guide member 32 mounted on a table portion or apron 34 of the broaching machine I0. A broach 36 secured in the broach holding fixture 30 is adapted to breach a plurality of longitudinal grooves 1n a portion of the periphery of a cylindrical work piece 38 held in position between a pair of relatively movable clamping jaws 4i) in a work holding fixture 42. The work holding xture 42 is pivotally mounted on a shaft 44 for movement to andfrom an o-pen position indicated in` full lines in Fig. l where .the work piece 38 may be applied to and removed from the fixture, and a closed position indicated in dotted lines in Fig. 1 for positioning the work piece 38 in axial alignment with the broach 36. A key 46 on the broach holding xture 30 is slidable in a key Way. in the work holding fixture in its closed position during forward movement of the remand prevents movement of the Work holdery 42 to open position until the ram I2 has completed its breaching stroke.

Mechanism is provided for automatically moving the work holder 42 from its closed position to its open position on completion of the forward or broaching stroke of the ram I2 and comprises an arm 56 secured at one end to the shaft 44 and connected at its outer end to one end of link 5I. The link 5I at its other end is connected to one end of an arm 52 which is secured at its other end to a shaft 53 mounted in suitable bearings in the guide member 32. A lever 54 also secured to shaft 43 has a forked end 55 which straddles the rod I4 and engages a relatively heavy helical compression spring 56 encircling the rod. The end portion 58 of an arm 59 secured to the ram I2 for movement therewith is adapted to engage the spring 56 near the end of advance movement of the ram I2 to move the spring 56 and the lever 56, and through the linkage associated therewith to cause the work holder 42 to be moved from its closed to its open position. A collar 51 fixed to the control rod I4 and engageable by the lever 54 serves to actuate the rod I4 automatically to its reverse position in response to the movement of the work holder 42 to its open position, to cause the ram I2 to return to its upper position. In machines where it is desirable to eliminate the automatic reversing of the ram and have the ram I2 reversed under manual control the collar 51 may be removed from its position as shown in Fig. 1 and be secured in a position on the rod I4 below the end I6 of the lever I1 to be actuated thereby in response to the actuation of the lever 26.

The safety mechanism limits the movement of the control means and the lever 26 to prevent the full movement thereof to and from its forward and reverse positions to cause the forward and reverse strokes of the ram I2 except under proper conditions. .The safety control mechanism comprises a control member in the form of a plate 60 provided with stop shoulders 6I and 62 for limiting the movement of the lever in opposite directions and formed byan irregular recess 63 in the plate through which a portion of the lever I1 extends. The plate 6I) is slidably mounted in a guide 65 secured to the side of the broaching machine III, for movement at right angles to the plane of movement ofthe lever I1. The guide 65 comprises a supporting plate 66 secured to the side wall of the broaching machine I by screws 61 and a pair of guideways 68 engaging the upper and lower edges of the plate 60. A vertical slot 66 formed in the plate 66 provides clearance for movement of the lever I1. A pair of tension springs 16 secured at one end to pins 1I on the ways 68 and at their other ends to pins 12 on the plate 60, serve to urge the plate 60 to the left as viewed in Fig. 3. A solenoid 15 is mounted on the plate 66 and has an armature 16 connected to one end of link 11 the other end which is pivotally connected at 18 to the plate 60. The solenoid when energized, serves to stress the plate V60 for movement with sufficient force to overcome the springs 10 and move the plate 60 to the right.

The movement of the plate 60 in opposite directions may be limited by any suitable stop means. In the present construction the movement of the control member 60 to the left is stopped by engagement of the lever I1 with the wall or edge 80 of the aperture 63 and the movement of the member Gilto' the right is stopped by the engagement of the lever I1 with wall or' edge 8| 0f the aperture 63. The intermediai: horizontal portion 82 of the aperture 63 defined by the wall 80 and 3l and stop surfaces 6I and 62 provides clearance for the lever I1 in its neutral position and permits horizontal movement of the member 6I) to and from its rst and second positions. Vertically extending slots 83 and 84 are formed by the ends of the aperture 63 in the plate in spaced relation to each other, the slot 83 extending upwardly between surfaces or walls and 85, and the slot 84 extending downwardly between the surfaces SI and 86. The recess 63 in effect, is formed by a pair of parallel vertically disposed slots partly offset vertically relative to each other and positioned side by side with portions of the slots communicating with each other.

With the member 66 in its normal or iirst position, Fig. 3, the slot 83 provides clearance for the movement of the lever I1 to and from its neutral and reverse positions and the wall 35 prevents movement of the member 60 to the right to its second position when the lever I1 is in its reverse position. With the member 60 in its seco-nd position (Fig. 4) the slot 84 provides clearance for the movement of the lever I1 to and from its neutral and forward positions and the wall 86 prevents movement of the member 60 to the left to its first position when the lever I1 is in its forward position. It will thus be seen that plate 60 functions in either of its two positions to prevent the full movement of the control lever 26 from one operative position to the other operative position and serves to limit the movement of the lever to and. from either one of the operative positionsand the neutral position. v

The solenoid 15 is connected to a source of current through a normally open micro-switch 66 (Fig. 1) which is mounted on the guide member 32 in a position to be actuated to a closed position by the movement of the work holding fixture 42 to its closed position. Thus, whenthe work holding fixture 42 is in its open position the micro-switch 96 is open, the solenoid 15 is deenergized and the plate 66 is stressed for movement to the left as viewed in Fig. 3 to its normal or rst position, and when the work holding fixture 42 is in its closed position the solenoid 15 is energized and stresses the plate 60 for movement to the right as viewed in Figure 3 to its second position.

In the operation of broaching a part 38, with the plunger I2 of the breaching machine in its upper position, the work holding fixture 42 in its open position, Vthe operating lever 26 is in its upper or reversing position and plate 66 is in its normal or first position with the lever I1 in theslotted portion 83 of the aperture 63 and freely movable to and from the reversing and neutral positions. A work piece 38 may be clamped in position between the clamping jaws 4U of the work holding fixture 42 and the iixture moved from its open position to its closed position to align the work with the broach 36. In response to the closing of the work holding fixture 42 the micro-switch 90 is actuated to close the circuit to the solenoid 10 and cause its energization which then stresses the plate 60 to the right to `its second position. The operating lever 26 may then be moved downwardly from its upper or reversing position into its neutral position in which position of the lever I1 the plate 60 is moved to the right to its second position by the solenoid 15 and the operatingvlever 26 may be moved downwardly from its' neutral position to its lower or forward position. The movement ofI the operating lever 26 downwardly fromv its upper position to its neutral position and. from its neutral posi-tion to its lower position is effected without any hesitation er stopping ofi the lever 26 in its neutral position by the plate 65.)', since the movement of slide plate 62 from its rst position to i-ts second position is so rapid so as not to interfere with the continuous movement of lever I1 and the operating lever 26.

In response to the movement of the operating lever 26 downwardly to its forward position the end I6 of the lever i1 as it moves upwardly engages the collar 20 and' moves the rod I4 upwardly' to cause the ram I2 and the breach te move downwardly through a breaching stroke to breach the Work piece 38. While the ramV I2 and the breach 36- are being advanced the operating lever 26 cannet be returnedto its upper or reversing" position to reverse the movement of the' breach 36 because of the stop surface 62 of the" plate' 60 which limits the upward movement of lver I1 and the `operating lever 26 to a neutral position and this construction insures that the breach cannot be returned te its original starting position prior to the completiony of its forward or breaching stroke and thus prevents any damage which might be caused to the breach by accidental reversal of the breach prior to the completion of its forward stroke. After the work piece 38 hasv been breached and near the end of the forward stroke ofthe ram l2 the end. 58 of the arm 59 carried by the ram engages the spring E6 and moves it and the lever 54 downwardly and causesy the work holding fixture 42 to be moved to its open position.

During the initial portion `of the movement of the werk holder 42 to its open position the switch 90 is returned to its normally open position and the solenoid is deenergized allowing the plate 66 to be stressed to the left to its normal or rst position. vAs the lever 54 is moved downwardly the bifurcated end 55 thereof engages the collar 51 on the red Hl and moves it downwardly to cause the ram l2 to be moved upwardly and the collar 26 en the rod i4 imparts movement to the lever Il and causes the levers l'lland 26 to be moved to their reverse positions. When the levers I1 and 26 reach the neutral positions during their movement from their forward to their reverse positions the plate 60 is immediately moved to the left with a snap action to align the slet 83 with the lever l1 to permit the levers Il and 26 to complete their movement without any interference from plate 60.

Although in the embodiment of the invention disclosed herein, the plate 60 of the safety interlock is shown as cooperating with the lever l1 to limit the movement of the control means. It will be understood that the plate 66 may be positioned to cooperate with the lever 26 er any element of the movable linkage comprising the control means to limit the movement of the control means in the same manner as disclosed above.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An interlocking device for a breaching machine having a breach actuating ram reciprocable in response te actuation of a control means including an element movable to and from forward,

6. neutral and reverse.v positions anda workhelding fixture .movable to.- and, from a. clesed positionfor holding, thework in alignmentA withsaid breach, said. interlocking device. comprising a member having portions deining. an. irregularl slot for receiving said element therein to limit the movement ef said control means, means mounting said member for movement-transversely to the movement of said lever to and from a first position andv a second position, said irregular slot having anY intermediate portion for receivingsaid element when said element is in neutral position te per.- mit movement of said member to and from its first and second positions, said irregular slot having a rst end portion extending transversely from said intermediate portion in one direction and operable when said plate is in said first positien forI receiving saidV element and limiting the movement thereof to and from reverse and neutral positions, said irregular slot having a second endportien extending transversely vfrom said intermediate portion in the opposite direction and operable when said plate is in said second position for receiving said element therein and limitin'g` the movement of said element to and from forward and reverse positions, and means operablein response to movement of said werk holding" xture from its, closed position te move said member to its first position and operable in respense-to the movement of said work holding xture to its closed position to move said member to its` second position.

.2'. An interlocking device for a breaching machine provided with control means including an element movable to and from forward, neutral and reverse positions for controlling the forward and reverse movements of a breaching tool, and a. work holding fixture movable to and from an operative position for holding the work in Athe path of the breaching tool, said interlocking device comprising a plate having an irregularly shaped aperture therein for reoeivingsaid element therein, means for mounting said plate for movement to and from a first position and a second position, said aperture having a straight intermediate portion providing clearance for said element to permit movement of said control plate to and from said first and second posit-ions when said element is in neutral position, said aperture having a pair of parallel end portions extending transversely from said intermediate portion in opposite directions and from opposite ends thereof, one of said end portions of said aperture serving to permit and limit movement of said element to and from reverse and neutral positions when said member is in its first position and the other of said end portions of said recess serving to permit and limit movement of said operating lever to and from forward and neutral positions when said plate is in said second position, resilient means urging the plate to said rst position, a solenoid operatively connected to said control plate for moving said plate to said second position when energized, and means including a switch actuated by the movement of said Work holding fixture to its operative position for energizing said solenoid.

3. An interlocking device for a machine having a breach actuating ram reciprocable in response to actuation of a control means including an element movable in a plane to and from forward, neutral and reverse positions and a work holding fixture movable to and from closed position for holding the work in alignment with said breach, said interlocking device comprising a plate having portions thereof defining a pair of slots for receiving said element therein, said pair of slots being disposed in a direction parallel to the plane of movement of said element and offset in said direction relative to each other and arranged side by side with portions thereof in communication with each other, one of said slots serving to limit the movement of said element to and from reverse and neutral positions and the other of said slots serving to limit the movement of said element to and from forward and neutral positions, means mounting said plate for movement transversely to the plane of movement of said element to and from a rst position and a second position to align alternate ones of said pair of slots with said element, said slots providing clearance for said element when said element is in neutral position to permit movement of said plate to and from said first and second positions, means yieldably urging said plate to its first position, and electrical means operable in response to the movement of said work holding xture to its closed position to urge said plate to its second position.

4. An interlocking device for a broaching machine having a broach actuating ram reciprocable under control of an operating lever which is movable to and from forward, neutral, and reverse positions, and a, Work holding fixture movable to and from a closed position for holding the work in alignment with said breach, said interlocking device comprising a plate having an aperture for receiving said control lever, means mounting said plate for movement transversely of the direction of movement of said lever, means for stressing said plate for movement in one direction to a rst position 'in response to movement of said work holding fixture from said closed position, and means for stressing said plate for movement in the opposite direction to a second position in response to movement of said work holding fixture to said closed position, the aperture in said plate having a contour permitting movement of said plate to and from said rst and second positions only when said lever is in said neutral position and limiting the movement of said lever to and from neutral and forward positions at said rst position of said plate and limiting movement of said lever to and from neutral and reverse positions at the secondposition of said plate.

5. An interlock for a machine having a control lever and linkage elements movable to and from forward, neutral, and reverse positions to control the forward and reverse movements of a tool on said machine and having a work holder movable to and from an operative position for holding the work in the path of said tool, said interlock comprising a member having an irregularly shaped slot therein for receiving a movable linkage element therein, means mounting the slotted member for movement transversely of the direction of movement of said element, means limiting the movement of said slotted member to and from a first position and a second position, the slot in said slotted member having a contour permitting movement of said member to and from said rst and second positions only when said element is in said neutral position and for limiting the movement of said lever and said element to and from neutral and forward positions when said slotted member is in said first position and for limiting the movement of said lever and said element to and from neutral and reverse positions When said slotted member is in said second position, spring means urging said slotted member for movement to one of said positions, and electrical means including a switch operable in response to the movement of said work holder to said operative position for moving said slotted member to the other of said positions.

CHARLES F. TRITELINE. BEN L. WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

Kelley sept. 19, 1944' 

